18results about How to "Suppress overvoltage" patented technology

The invention discloses a grounding system of a high-voltage switch cabinet, relates to the technical field of power systems, and solves the problems of poor resistance stability and poor safety in a grounding system of an existing high-voltage switch cabinet. The system comprises a real-time detection module, a self-adaptive grounding resistance adjusting module, a high-frequency transient suppression module, a fault detection and isolation module, a grounding current control module and a remote measurement module. The multi-section controllable resistor is connected with the grounding path in series, the resistance value is automatically adjusted by combining the environment compensation model, it is ensured that the grounding resistor is kept stable under different environment conditions, arc light reignition is detected and rapidly responded through the high-frequency transient suppression module, and generation of overvoltage is effectively suppressed; grounding current is monitored in real time through the fault detection and isolation module, further diffusion of faults is prevented, and reliability and safety of the system are improved; according to the invention, the resistance stability and safety of the existing grounding system are greatly improved.

The invention discloses a flexible dynamic low-frequency wind power system multi-body coordination ride-through control method and system, and the method comprises the steps: obtaining the voltage of a power frequency system, and inputting a power-matched low-frequency AC energy consumption device according to the power of the power frequency system before a fault when the fault of the power frequency system is judged according to the voltage of the power frequency system. According to the method, overvoltage and overcurrent in the flexible dynamic low-frequency wind power system can be effectively reduced, and the fault ride-through performance of the system is improved.

The present invention discloses a method, device and storage medium for suppressing overvoltage of SLCC converter valves, the method comprising: obtaining a first extreme working condition by traversing overvoltage fault scenarios through simulation, and optimizing the bridge arm reactor parameters according to the first extreme working condition to obtain a first scheme for suppressing overvoltage; when the first scheme cannot effectively suppress overvoltage, simulation is performed based on the first extreme working condition and the optimized bridge arm reactor parameters, and the valve-controlled unbalanced protection action constant is optimized to obtain a second scheme for further suppressing overvoltage; when the second scheme cannot effectively suppress overvoltage, simulation is performed based on the optimized bridge arm reactor parameters and the valve-controlled unbalanced protection action constant to obtain a second extreme working condition; based on the second extreme working condition, combined with engineering requirements, the converter valve assembly is optimized until a scheme that can effectively suppress overvoltage is obtained. The present invention realizes effective suppression of overvoltage of SLCC converter valves through the joint design of primary and secondary systems.

The invention relates to the technical field of power system protection, and discloses a condensed state function resistor NGR-based power grid safety and stability protection device and method, and the device comprises a three-phase bus A, a bus B and a bus C. The bus A, the bus B and the bus C are respectively provided with a circuit breaker DL, and the two ends of the fracture of each circuit breaker DL are respectively connected with a first condensed state function resistor NGR in parallel. And the bus A, the bus B and the bus C are connected with a second condensed state functional resistor NGR and a first ampere meter in a star connection hanging manner. According to the power grid safety and stability protection device and method based on the condensed state function resistor NGR, short-circuit current and overvoltage in a power grid are suppressed through various functional characteristics of the condensed state function resistor NGR, electromagnetic resonance and system oscillation in the power grid are reduced, and operation of the power grid is stabilized; the first ampere meter and the second ampere meter are used for detecting each path of current in real time, so that the timely finding and processing capability of power grid faults can be improved.

The suppression assembly comprises a mutual inductor shell, a magnetic screen mutual inductor shell in the mutual inductor shell is structurally designed to comprise an electromagnetic wave reflecting layer and an electromagnetic wave absorbing layer, one side of the mutual inductor shell is provided with an arc-extinguishing and resonance-eliminating mechanism, the arc-extinguishing and resonance-eliminating mechanism comprises a resistor resonance-eliminating piece, a capacitor and an arc-extinguishing cover, and the resistor resonance-eliminating piece is connected with the capacitor and the arc-extinguishing cover. The arc extinguishing chambers are arranged on the periphery of the primary wiring terminal in the mutual inductor shell; according to the suppression assembly for the PT open delta winding, resonance is suppressed through the resistor resonance elimination piece to generate overvoltage, a voltage transformer is prevented from being burnt out, the arc extinguishing cover is arranged on the periphery of the primary wiring terminal in the transformer shell and used for attracting the overvoltage generated by the primary wiring terminal, and the voltage transformer is prevented from being burnt out. And a large amount of energy generated by overvoltage is transmitted and stored into the capacitor through the connecting seat, the cross block, the fixed block I, the lifting telescopic rod and the telescopic guide cylinder which are connected, so that the overvoltage is absorbed, and the voltage transformer is prevented from being burnt due to long-time overvoltage.

The application discloses a full-automatic variable-distance flexible grabbing system and a control method thereof, converts mechanical adjustment of X-axis, Z-axis and Y-axis into electrical parameter adjustment, and provides two control methods which are special for a clamping module of the full-automatic system and are used for servo drivers of the clamping module, namely, a software multi-circle backup is used to replace an internal battery of an encoder, and cross-rolling verification is combined, so that the servo driver of the clamping module can directly enter a clamping ready state without returning to an original point mechanically after being powered on; and a weak magnetic control algorithm is used to suppress reverse electromotive force from a source, replace passive protection devices on a sensor signal line, and guarantee that multi-sensor AND fusion determination logic is continuously reliable in a full-speed section. The application eliminates two delay sources of initialization waiting and sensor failure, and realizes a complete closed loop from structure to control, and releases a formula to zero-second transformation.

The application discloses a photovoltaic grid-connected system and an alternating current fault ride-through method and device thereof, and comprises a plurality of photovoltaic arrays, a plurality of photovoltaic grid-connected inverters, a direct current collection line and a step-up transformer. Each photovoltaic grid-connected inverter is composed of six bridge arms, wherein each bridge arm comprises a plurality of photovoltaic sub-modules; each photovoltaic sub-module comprises a front-stage MMC converter sub-module and a rear-stage DC-DC converter. When an alternating current fault occurs in the photovoltaic grid-connected system, a hierarchical three-stage control of a photovoltaic converter stage, a bridge arm stage and a sub-module stage is combined to independently regulate the output of each photovoltaic sub-module, ensure that photovoltaic MPPT control is not completely disabled during the fault ride-through, inhibit overvoltage of the photovoltaic sub-module when the grid voltage drops, and realize the alternating current fault ride-through of the photovoltaic grid-connected system.

An anode gas diffusion layer for a water electrolysis cell includes metal fiber. The metal fiber has a section. The section constitutes a surface of the metal fiber. The section is composed of nickel. A water electrolysis cell includes an anode, a cathode, and an electrolyte membrane. The electrolyte membrane is disposed between the anode and the cathode. The anode includes the anode gas diffusion layer for the water electrolysis cell.

A kind of combined grid-friendly photovoltaic confluence system for 5G base station, including confluence unit, sensing unit, photovoltaic power generation system is accessed to direct current bus through confluence unit;Sensing unit collects distribution network voltage information and is transmitted to confluence unit in real time;Confluence unit according to distribution network voltage and direct current bus voltage, dynamically adjusts output power.Confluence unit includes: main power circuit, auxiliary power supply circuit, sampling circuit, drive circuit, control module, protection circuit, first wireless communication module.Sensing unit includes: single-chip microcomputer, wireless communication module, ac power grid power quality monitoring unit, auxiliary power supply.The utility model discloses a kind of combined grid-friendly photovoltaic confluence system for 5G base station, to be able to cope with 5G base station inside direct current bus overvoltage problem, simultaneously can according to the distribution network voltage of surrounding node, dynamically adjust power output, improve the stability of power supply system.

The application discloses a kind of coordinated control method and system for inhibiting power grid overvoltage, according to grid voltage and phase modifier steady-state displacement, construct the control strategy of reactive power source for inhibiting power grid overvoltage, in the control strategy of reactive power source, consider the voltage counter-regulation caused by the action delay of SVC, only after DC commutation failure according to grid voltage trajectory Trigger SVC coordinated control, in the case of power grid overvoltage, add phase modifier to DC reactive power compensation system, make it with original converter station filter, DC reactive power compensation capacitor coordinated as the operation of new DC reactive power compensation system, according to grid voltage situation Control phase modifier and SVC, realized that multiple types of reactive power source inhibit power grid whole process overvoltage, improve the voltage comprehensive control level of high proportion new energy DC external sending system.

The invention discloses a voltage test loop and method for state inspection of an extra-high voltage AC circuit breaker, and the test loop comprises a first voltage source which is connected in series with one end of a tested circuit breaker, and is provided with a first control switch; the second voltage source is connected in series with the other end of the tested circuit breaker, and a second control switch is arranged on the second voltage source; wherein the first control switch is used for controlling the first voltage source to apply voltage to one end of the tested circuit breaker; and the second control switch is used for applying voltage to the other end of the tested circuit breaker by the second voltage source at a specific time. According to the test loop, the first voltage source and the second voltage source are utilized, the test loop for the voltage test of the ultra-high voltage alternating-current circuit breaker for state inspection and the control method are established, and compared with a traditional voltage source test loop, the control precision is high; according to the method, overvoltage generated during breakdown of the tested circuit breaker can be suppressed by using the resistor R3, and the resistor R3 can adjust waveform parameters according to standard requirements.

The present invention relates to a closing surge suppression device for reactive compensation in the field of reactive compensation in distribution networks. The device is installed on the incoming line side of a capacitor group for reactive compensation, and includes a voltage transformer, a current sensor, a circuit breaker, a fast switch, a phase control device, and a controller. When the capacitor group needs to be put into operation, the capacitor group can be put into operation by first closing the circuit breaker, so that the surge generated when closing the circuit breaker is first suppressed by the phase control device; then the fast switch is closed to exit the phase control device, and the capacitor group remains in operation. In the case of presetting multiple protection branches, each protection branch is connected to a control device respectively, and the control device can realize automatic control by using the size of the closing surge current, so that a corresponding number of protection branches can be put into operation as needed in the process of eliminating the surge peak.

The utility model provides a multi-section type intermediate frequency welding signal acquisition circuit which comprises a control module, a switching module, a first voltage acquisition module, a second voltage acquisition module and a current acquisition module, and the input end of the switching module is electrically connected with the output end of a pressure sensor and the secondary output end of a transformer. The output end of the switching module is electrically connected with the input end of the first voltage acquisition module and the input end of the second voltage acquisition module, and the first voltage acquisition module and the second voltage acquisition module are connected with the feedback output end of an external pressure sensor and the secondary output end of a transformer through the switching module. The voltage measuring module is used for respectively measuring feedback voltage of the pressure sensor and secondary voltage of the transformer, an output current value during welding can be acquired through the current acquisition module, a welding resistance value is calculated according to the acquired voltage value and current value, then the state of a welding spot and welding quality can be judged according to resistance, and the welding quality can be effectively improved.

The present invention relates to a large-scale power transformer excitation system and method for a circuit system for power supply and distribution. The excitation system includes an excitation system transformer, a low-voltage side switch and an excitation surge current suppression device, and the excitation surge current suppression device includes a phase-controlled main circuit, a bidirectional current suppression module and an inrush current control unit. The excitation surge current suppression device allows the transformers running in parallel to serve as power sources for each other as backup, thereby ensuring the stability and reliability of the power grid system and reducing the negative impact on the electricity consumption of residents covered by the power grid system. In particular, for enterprises that rely on high-quality power supply, the stability and power supply reliability of the power grid system ensure the electricity demand of the enterprise's production and reduce production losses caused by power outages.

The invention discloses a capacitor aging transient current short circuit elimination method, and relates to the technical field of capacitors, and the capacitor aging transient current short circuit elimination method comprises the following steps: S1, using an overcurrent protection circuit; s2, using a current-limiting resistor; s3, using a transient voltage suppressor; s4, using automatic detection and data monitoring; s5, a thermistor (PTC) and an MOSFET switch are used after the step S4, and a fuse and a resettable fuse are additionally installed at the front end of a capacitor in the circuit in the step S1; the method for installing the fuse at the front end of the capacitor is the simplest method. According to the method for eliminating the short circuit of the capacitor aging instant current, the automation degree of the device is improved through S4 and S5, the short-circuit capacitor can be detected in time before the capacitor enters the aging machine, and the short-circuit capacitor is eliminated, so that the short-circuit capacitor is prevented from influencing the aging work of other normal capacitors, and the service life of the capacitor is prolonged. Therefore, the stable output of the product is improved.

The utility model discloses an overvoltage suppression device of a steel rail potential limiting device, when a steel rail potential limiter is switched on, a direct current contactor K2 is switched on, a solid-state relay K3 is switched on, a non-polar capacitor Cs1 is charged by a 220V AC / DC charging loop, when the voltage at the two ends of the non-polar capacitor Cs1 reaches 300V, the solid-state relay K3 is switched off, and the charging process is completed within 3 seconds; when the steel rail potential limiter is switched off and a 25V voltage difference is detected between a steel rail and the ground, the control system triggers the controllable semiconductor device SCR1 and the controllable semiconductor device SCR2 to be switched on, so that a reverse current arc extinction loop is formed, and steel rail overvoltage generated when the steel rail potential limiter is switched off is suppressed; and after the capacitor is reversely charged, the controllable semiconductor device SCR1 and the controllable semiconductor device SCR2 are cut off. According to the invention, a piezoresistor or a lightning arrester is not needed, and when a line suffers from frequent overvoltage impact, the overvoltage of the steel rail can be rapidly suppressed.

The invention discloses a power-adaptive energy storage converter control method and system. According to the method, the problems of overvoltage and undervoltage of a grid-connected point and overcharge and overdischarge of an energy storage battery can be effectively solved by controlling adaptive charge and discharge of the energy storage battery. Firstly, grid-connected point voltage is sampled for effective value processing, a grid voltage effective value feedback signal Ugfrms is obtained and sent to the inverted input end of a voltage error amplifier, and a grid voltage reference Uref is sent to the in-phase end of the voltage error amplifier. The output Ue of the voltage error amplifier is subjected to a positive and negative amplitude limiting link to obtain Ue1, and the Ue1 is sent to one input end of the multiplier. And the charge state signal Soc of the energy storage battery is subjected to range judgment to obtain a state signal J, and the state signal J is sent to the other input end of the multiplier. And the output Iref of the multiplier and the charging current sampling signal Ibf of the energy storage battery are respectively sent to the non-inverting input end and the inverting input end of the current regulator. The output of the current regulator serves as a modulation signal and is sent to the PWM modulator.

The invention discloses a high voltage ride through control method for an equivalent dynamic Crowbar wind storage system with no power support, and the method comprises the steps: enabling an energy storage system ESS to be connected with two ends of a DC bus of a wind power generation system DFIG in parallel through a bidirectional Buck-Boost DC-DC converter, and monitoring the voltage of a grid-connected point of the wind power generation system DFIG; if the voltage does not exceed the preset threshold value, it is judged that the wind power generation system is in a normal operation state, a grid-side converter GSC, a rotor-side converter RSC and an energy storage system ESS adopt a conventional control strategy, otherwise it is judged that the wind power generation system is in an HVRT operation state, the grid-side converter GSC cooperates with the energy storage system ESS to carry out reactive power support, direct-current bus overvoltage in the HVRT period is restrained, and the voltage of the wind power generation system is restrained. A rotor side converter RSC simulates a Crowbar circuit to carry out equivalent dynamic Crowbar circuit control, and stator and rotor currents of a DFIG during an HVRT period are suppressed. According to the invention, when the PCC voltage rises, the grid-side converter GSC cooperates with the energy storage system ESS to carry out reactive power support, and the rotor-side converter RSC simulates a Crowbar circuit, so that the HVRT capability of the DFIG is improved.